Research On Control Platform Design And Simulation Computation Of Marine Electric Propulsion System

With the great development of electric semiconductor technology, the frequency control theory, modern control theory, the design and manufacturing technology of motor, the development of ship electrical propulsion technology is rapid. All kinds of electric propulsion equipments have been widely used in icebreaker, fishing vessel, liner and other vessels in recent years. The method of simulation experiments on the test equipment is an important research way in the electric propulsion field, thereby the control platform of the test equipment is designed, some simulation experiments are carried out, this work plays an important role to promote the develop of electric propulsion technology. The subject supported by the program of "laboratory of ship intelligent micro-grid and electromagnetic propulsion" from Dalian Maritime University, based on the original hardware, the control platform has been designed and a series of simulation experiments have been done on the platform.The overall design based on the analysis of the load simulation system of electric propulsion system is completed. An integrated plan for simulation is proposed, which integrates configuration software with simulation system via OPC communication technology. Besides, the speed and torque scaling method of propulsion system is determined.The human machine interface system combines graphic display technology which developed by configuration software WinCC. It consists of communication system, interface system, e.g., it has many functions, such as:process control, real time dynamic display, detection and alarm, and so on.According to the principle of ship propulsion, the mathematical model of ship-propeller system is established with the integral method. On the basis of the mathematical model, the load simulation model is developed in Matlab/Simulink environment, This model consists of three parts:input/output interface, load calculation sub module, torque translation sub module. This model can output load control command, which meets the requirement of propeller characteristic.Generally, the four quadrant data of marine propeller is difficult to obtain, to solve this problem, a propeller is designed and its characteristic is predicted. On the condition of ship parameters is known, the marine propeller parameters is determined by Wageningen B series and empirical formula, and then the four quadrant characteristic of the propeller is predicted by feedforward neural network algorithm. Therefore, the thrust coefficient and torque coefficient of the simulation model have been gained.A series of working conditions of ship have been simulated on the platform, such as:ahead condition, stop condition and astern condition. The stability of the control system and the correctness of the simulation model are proved by the experiment results, the goal of simulating the marine propeller load characteristic is achieved.This test equipment and its control system not only could provide an environment for teaching and program demonstration, but also have a reference value for other types load simulation in engineering.